VOLCANOES

Tectonics of Magma

• Basaltic magma– From partial melting of mantle– Occurs at oceanic ridges and mantle plumes– More dense: makes oceanic crust

• Granitic magma– From melting of crust, with water as flux– Occurs at convergent boundaries– Less dense: makes continental crust

Mt St Helens Before

http://www.ncusd203.org/north/depts/science/slack/mt_helens.html

Hawaii

http://volcano.und.nodak.edu/vwdocs/volc_images/north_america/hawaii/big_island.html

Kilauea

http://www.fhvnp.org/albums/seminar_1142006.htm

Low viscosity lava

http://smart.tin.it/domsky/4/fotos-imagenes/immagini/1/2002_07_28_archive.html

Ash of Mt St Helens

Terms

• Viscosity: resistance to flow• Pyroclastic: material blown into the air by

volcanic eruption• What is the relationship of lava viscosity to

pyroclastic production by a volcano?• Greater viscosity=more likely to have

pyroclastic material

Lava character

• Volcanic gas information below

http://volcanoes.usgs.gov/Hazards/What/VolGas/volgas.html

Kilauea spatter cone

http://www.billystudio.com/photo_album/Big_Island/Volcano_Park_Slide/pages/Kilauea%20Spatter%20Cone%201984.htm

MtStHelens

http://www.geology.mcmail.com/volcanoes.htm

Ash Bed

http://www.wooster.edu/geology/bjordan/ECalPics/ECal.html (dead link 2007.11.13)

Volcanic bombs

http://volcanoes.usgs.gov/Products/Pglossary/bomb.html

Ash of Mt. St. Helens

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Mt St Helens After

http://www.ncusd203.org/north/depts/science/slack/mt_helens.html

Sept. 2002

Photo credit see http://www.roddyscheer.com/mt_st_helens.html

Volcanocam see http://www.fs.fed.us/gpnf/volcanocams/msh/

Pahoehoe lava

http://www.doubledeckerpress.com/pahoe.htm

Pahoehoe

http://gaia.busanedu.net/~creative/2002/cyber/rock/pages/20651_pahoehoe.htm

Pahoehoe

http://www.mistermoose.org/rtw/usa/hawaii/pahoehoe.html

AA

http://www.windows.ucar.edu/earth/geology/images/aa_pahoehoe_lg.jpg

Welded tuff

http://www.wooster.edu/geology/bjordan/ECalPics/ECal.html

Ash Bed

http://www.wooster.edu/geology/bjordan/ECalPics/ECal.html

bomb

http://www.volcanicimages.com/krakatau/krakatau.html

Volcanic bombs

http://volcanoes.usgs.gov/Products/Pglossary/bomb.html

Mt Hoodhttp://www.geog.utah.edu/~hmiller/photos/Mt_Hood.jpg

Fujiyama

http://earth.geol.ksu.edu/sgao/g100tu/plots/1008_composite_volc_Fujiyama.jpg

Paricutin

http://www.bol.ucla.edu/~asuarezn/Paricutin_page.html

Crater Lake

Kilauea Caldera

http://www.globalgeografia.com/album/oceania.htm

Shield volcano

http://volcanoes.usgs.gov/Products/Pglossary/ShieldVolcano.html

Shield volcano

http://earth.geol.ksu.edu/sgao/g100tu/plots/1008_shield_volc.jpg

Curtain of fire

http://www.uhh.hawaii.edu/~csav/gallery/decker/hawaii_curtain_of_fire.php

Lava fountain from fissure

Active Lava Tube

http://www.doubledeckerpress.com/skylight.htm

Parícutin

http://www.greenville.k12.oh.us/volcano/cindercone.html

Cinder cones

http://courses.unt.edu/hwilliams/GEOG_3350/examreviews/volcanic_structures.htm

Cinder cone

Ash from Paricutin

http://www.greenville.k12.oh.us/volcano/cindercone.html

Paricutin

http://www.bol.ucla.edu/~asuarezn/Paricutin_page.html

San Juan Parangaricutiro

http://www.bol.ucla.edu/~asuarezn/Paricutin_page.html

Mt Etna

http://rst.gsfc.nasa.gov/Sect13/Sect13_4d.html

Aspects of volcano types

Composite cone

http://courses.unt.edu/hwilliams/GEOG_3350/examreviews/volcanic_structures.htm

Ring of fire

http://pubs.usgs.gov/gip/dynamic/fire.html

Cascade Volcano eruptions

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Mt Hoodhttp://www.geog.utah.edu/~hmiller/photos/Mt_Hood.jpg

Blasted summit of Mt. St. Helens

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Whaleback dome in Mt. St. Helens

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Nuee Ardente

Martinique

http://www.geology.sdsu.edu/how_volcanoes_work/Pelee.html

Martinique

Video of nuee ardente: http://www.bedford.k12.ny.us/flhs/science/apes/images.htmlhttp://www.geo.mtu.edu/volcanoes/west.indies/soufriere/govt/images/051296/pf_sea.mpg

St Helens Blast Zone

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Lahar

Link to Nevado del Ruizhttp://volcanoes.usgs.gov/Hazards/What/Lahars/RuizLahars.html

St Helens Deposits

http://ve.ou.edu/weaver/st_helens/sthelens.htm

Crater Lake

Caldera initial stage

Caldera final stage

Kilauea Caldera

http://satftp.soest.hawaii.edu/space/hawaii/nav/ap.kilauea.html

Kilauea Caldera—Stage 1

http://hvo.wr.usgs.gov/howwork/subsidence/inflate_deflate.html

Kilauea Caldera—Stage 2

http://hvo.wr.usgs.gov/howwork/subsidence/inflate_deflate.html

Kilauea Caldera—Stage 3

http://hvo.wr.usgs.gov/howwork/subsidence/inflate_deflate.html

Valles Grande

http://ve.ou.edu/weaver/votw/valles.htm

Flood basalt

Flood basalt

http://www.bedford.k12.ny.us/flhs/science/images/floodbasalt.jpg

Flood basalt

http://www.gly.uga.edu/railsback/FieldImages/BasaltTwinFalls.jpeg

Deccan basalt

http://www.accuracyingenesis.com/deccan.html

Shiprock

http://www.uwosh.edu/faculty_staff/muldoon/51-360/Moes_pics/pages/6B_Ship_Rock_gif.htm

Volcanic summary